Indicating device for water-tanks



G. M. DAVIS.

INDIOAT E FOR WATER TANKS.

' Patented Nov. 10,1891.

NITED STATES PATENT OFFICE.

GEORGE M. DAVIS, OF CHICAGO, ILLINOIS.

INDICATING DEVICE FOR WATER-TANKS.

SPECIFICATION forming part of Letters Patent No. 462,837, dated November10, 1891.

Application filed February 19, 1891. Serial No. 382,049. (No model.)

To aZZ whom it may concern.-

Be it known that I, GEORGE M. DAVIS, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in an Indicating Device forIVat-er-Tanks, of which the following is a full, clear, and exactdescription, that will enable others to make and use the same, referencebeing had to the accompanying drawings, forming a part of thisspecification.

The object of this invention is to providea device to indicate thevolume of water contained in a tank or reservoir located in the upperpart of a building, the indicator being placed in the lower part orbasement convenient to the engineer or other attendant. By means of myarrangement the height of the water is known at a glance, no matter whatthe intervening distance may be between the tank and indicator.

In the drawings, Figure 1 is a side elevation showing a practicalapplication of my device, and Fig. 2 a vertical longitudinal section ofthe indicator.

Referring to the drawings, A represents a water-tight cylinder placed ina vertical position; B, a traveling piston or diaphragm located therein,and C a spiral spring placed inside of said cylinder, one end resting onthe bottom thereof and the opposite end bearing against the under sideof the piston, as shown. The piston consists of two conoavo-convex disksa a, with the flexible packing a clamped between, as shown in Fig. 2.The upper disk at is of a less diameter than the lower companion disk,so that the annular edge of the packing may be turned upwardly, as shownin Fig. 2, and thereby increase its bearingsurface 011 the interior wallof the inclosingcylinder, so as to form a water-tight joint withoutcausing so much friction as to prevent a free movement of the piston.The lower end of the indicating-rod b is secured in the upper side ofthe piston and extends up into the glass tube Z), properly mounted onthe upper end of the indicator inclosed by the metal tube 12 which iscut away on the front side, as at 17 thereby exposing the correspondingfront of the glass tube and preper end of the main reservoir, and isconnected thereto by the tube (Z.

The water-pipe G connects the lower end of the auxiliary reservoir withthe upper end of the indicator-cylinder. The purpose of the smallauxiliary reservoir is to maintain a constant excess pressure on theupper side of the traveling piston. By this arrangement the indicator isconnected to the main reservoir by two columns of a different pressure.This pressure is of course variable, very little, however, between theupper end of the indicator and the top of the main reservoir, as theauxiliary reservoir will be nearly always full, as the volume containedtherein will be lessened only a little when the water in the mainreservoir is lowered and the piston 011 the downstroke. The auxiliaryreservoir will therefore maintain a constant and uniform head. Thepressure or head through the under side of the indicator will of coursevary in a greater degree in accordance with the volume of water in themain reservoir. The spring serves the purpose of balancing thedifference in pressure between the two columns. The weight or tension ofthis spring must be determined by the vertical dimensions of the tankand the piston area of the indicator. The lugs g 9 provide means forsecuring the indicator to some stationary ob ject.

IVhen the indicator is placed in position the cylinder must be filledwith water on both sides of the piston. Now, as the waterin the tank ormainreservoir lowers, the piston moves downwardly, and when refilled itmoves in the opposite direction, which movement is made apparent by thecorresponding movement of the indicating-rod in the glass tube and theheight of the water in the reservoir, known at a glance; As the pistonmoves upwardly, the excess or overflow will escape into the tank throughthe tubular contiuua- 7 tion connecting the tank and auxiliaryreservoir.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. In an indicator of the character described, the combination, with awater-tight cylinder having a glass tube mounted thereon, of a travelingpiston. located in said cylinder and carrying an indicating-rod, whichextends into said tube or chamber, a spring bearing against said piston,a tank vor reservolr, the water-pipes connecting the respect- GEORGE M.DAVIS. Witnesses:

L. M. FREEMAN, L. B. COUPLAND.

